Professional athletes, sports enthusiasts or people who like exercise often evaluate their own physical conditions during exercises, and thus configure their own physical strengths in order to complete an exercise or a competition. Typically, people evaluate their own physical conditions and environmental factors before or during an exercise to adjust their workouts. In addition, after an exercise, people record and analyze their physical strengths and endurances as references for the next exercise.
Recently, various types of exercise assistive devices have been developed to assess a user's physical strength in real-time. These devices are capable of providing users with their own physiological signals during exercise, and providing the user with exercise history records for browsing after exercise, and sharing the records with social networks. However, the indication of physiological signal, such as heart rate, often cannot be reliably and accurately correlated to the user's physical strength and endurance. Namely, the provision of only the physiological signal is of no or little effect for the user to decide when the used needs to decrease or increase the intensity during the exercise (i.e. when to slow down or speed up during marathon).
In view of the above, what is needed is an exercise assistive device and method which reliably indicates a stamina level of each of the users regardless of the differences of the physical condition among each of the users.